1. Field of the Invention
The present invention relates to an ink cartridge adapted for an ink jet printer, and particularly relates to an ink cartridge that can improve the ink leakage problem for additional events, such as squeezing the ink cartridge, delivery or long-period storage.
2. Background of the Invention
The ink jet recording technology is such as to record characters and images directly on a recording medium (such as paper, cloth, or plastic sheet) by discharging ink from fine nozzles thereto. Conventionally, the recording apparatus has been utilized as a printer serving and provided as the output terminal of a copying machine, a facsimile equipment, a printer, a word processor, a work station or the like; or as a handy or potable printer used for such an information processing system as a personal computer, a host computer, an optical disc device or a video apparatus. In a conventional recording apparatus, ink is supplied to a recording head from an ink tank constructed as a cartridge. A benefit of using the conventional ink cartridge serving as an ink tank is that the ink does not smear due to the leakage of ink while refilling new ink or the like. Nevertheless, undesired air bubbles can easily enter the ink tank during the filling process, which cause problems such as ink supply failure. Air trapped in the cartridge adversely impacts the ink supply to the printhead or can mix in the ink resulting in poor printing quality. To fill the ink cartridge by introducing the ink via a vacuum into the porous foam is used in an effort to limit the introduction or retention of the air bubbles in the ink cartridge.
The uses of the ink cartridge that improves various problems are disclosed in U.S. Pat. No. 6,761,441 B2, entitled “Ink Cartridge”, U.S. Pat. No. 6,619,790 B1, entitled “Ink-Jet Printer Cartridge Upper Cover”, U.S. Pat. No. 6,378,219 B2, entitled “Ink Cartridge”, and documents related thereabout. The advantages of reference U.S. Pat. No. 6,761,441 are that it provides an accommodating chamber defining a dimension completely same as that of ink porous member so that the ink porous member is impregnated with ink under low atmospheric pressure thereby to increase the amount of the impregnated ink, and further provides a stopping member having a sealing film integrally formed without a laminated film sealed on an opening of the ink outlet port. The advantages of reference U.S. Pat. No. 6,619,790 are that it provides a non-rigid ring sealed between an upper cover and vent tip, and further provides tight seal with a cover for saving time and labor. The advantages of reference U.S. Pat. No. 6,378,219 are that it provides the elastic member for unidirectional ventilation by a pressure difference between inside and outside the hollow ink tank body without both air inlet hole and porous member. Obviously, a pressure regulator referred in these prior art is used to maintain the pressure and ink flow to the printhead continuously. However, if accidental events happen, such as squeezing the ink cartridge, delivery or long period storage, ink leakage out of the pressure regulator occurs. Alternatives of regulator pressure have been explored but have failed to adequately address the leakage issue.
It is desirable to develop a new and improved ink cartridge to substantially resolve the leakage problems and provide better, more advantageous overall results.